1. Field of the Invention.
The invention concerns novel quinolylaminobenzoylpiperazine-1-oxides, hydrates thereof and pharmaceutically acceptable acid addition salts thereof; compositions prepared therefrom and methods of their use.
2. Description of the Prior Art.
Prior hereto, 4-alkyl- and 4-benzyl-1-[p-[[(trihalomethyl)-4-quinolyl]amino]benzoyl]piperazines were known as was their use as antihypertensives; see for example British Patent 1,268,469. Such compounds are starting compounds for the preparation of the corresponding N-oxides of this invention.
U.S. Pat. No. 3,632,761 describes a number of 4-alkyl-and 4-benzyl-1-[p-[(4-quinolyl)amino]benzoyl[piperazines and their use as antihypertensives. These latter compounds are also starting compounds for the preparation of the corresponding compounds of our invention.
U.S. Pat. No. 3,136,769 discloses a number of 4-amino-quinoline-1-oxides and their use as antiparasitic agents.
Prior hereto, it was generally accepted that the N-oxides were distinctly different chemical entities from the corresponding non-oxide compounds. In general, the N-oxides and the analogous non-oxides were thought to share few properties in common. It was, therefore, surprising to find that the N-oxides of our invention possess properties which make them useful as antihypertensive agents, sharing this property with the non-oxide analogs. An advantage found in the N-oxide compounds of our invention is their improved aqueous solubility over the parent compounds, making them useful in a wider variety of pharmaceutical preparations and uses.